Field of the Invention
This invention relates to circuit makers and breakers and in particular to high current capacity circuit makers and breakers having an arc-extinguishing chute to interrupt the current, and more particularly to a device of this type having an interlock arrangement to prevent closure of the electrical contacts of the circuit maker and breaker if the arc chute is improperly positioned or is entirely absent.
Circuit interrupters of high-current capacity such as direct current contactors usually have an arc-extinguishing chute which is removable to permit inspection, maintenance and repair of the contacts and/or of the arc chute. IF the circuit maker and breaker (or contactor) should attempt to open to interrupt the electrical circuit under overload conditions with the arc chute removed from or improperly assembled on the contactor, serious consequences could result, including serious damage to the contacts of the contactor.
It has been known in the prior art to provide interlock arrangements for preventing initial closure of the contactor if the arc chute associated with the contactor is improperly assembled on or is removed from the contactor. Examples of such prior art interlock arrangements are shown, for example, by the following U.S. Pat. Nos. 1,731,200 issued to George W. O'Keeffe on Oct. 8, 1929; 3,612,796 issued to Gustav W. Doos on Oct. 12, 1971; and 3,728,506 issued to Arthur C. Heehler et al on Apr. 17, 1973.